A need has developed to limit user access in data networks for security or other purposes. In recent years, buildings/offices are being equipped with different information networks, each having access to different data. It is important to restrict access to these networks to only authorized users. While some restrictions may be achieved using software approaches, such as passwords, the applicants have identified the need to restrict access further using some type of “physical barrier” to the networks. The present invention fulfills this need among others.